1. Field of the Invention
The present invention relates to an automotive air-conditioner having a film damper for both controlling the temperature of conditioned air and opening and closing an outlet.
2. Description of the Related Art
The prior art automotive air-conditioner uses a film damper for opening and closing an outlet. For example in Japanese patent laid-open publication No. 63-166618, film dampers are adopted not only for opening and closing an outlet but also for controlling the temperature of air flowing into a passenger compartment respectively. This is accomplished by adjusting the air-mixing ratio of air passing through the heater core and air passing through a bypass passage that bypasses the heater core. That is to say, the above prior art automotive air-conditioner has a pair of film dampers for (1) controlling the temperature of the air and for (2) opening and closing an outlet. Such film dampers inevitably need space for working. Therefore it is difficult to save space. Further, the increases in number of parts by the use of two film dampers for one outlet increase production costs. As shown in FIG. 9, another prior art automotive air-conditioner has one rotary damper for controlling the air-mixing ratio of heated air and cooled air and for opening and closing an outlet.
The air-conditioner shown in FIG. 9 comprises a refrigerant evaporator 100 and a heater core 101 in a casing 102. The heater core 101 is positioned downstream of the evaporator 100. The air from the fan (not shown) all flows through the evaporator 100. However, the heater core 101 is so disposed in the casing 102 that a bypass passage 103 is defined between the heater core 101 and an inner wall of the casing 102. The bypass air outlet 110 is disposed downstream of the bypass passage 103 through which air from the evaporator 100 flows into an air-mixing chamber 107. A heated air outlet 109 is disposed downstream of the heater core 101. Heated air flows through the heated air outlet 109 into the air-mixing chamber 107. An air outlet 105 is disposed downstream of the air-mixing chamber 107. Air mixed in the air-mixing chamber 107 flows into the passenger compartment through the air outlet 105. The rotary damper has an arc portion 106 of which size fits the largest of the three outlets. A rotary damper 104 is pivotally disposed in the air-mixing chamber 107 for selectively directing the arc portion 106 to one of the outlets 105, 109 and 110. Thus, the rotary damper 104 can adjust the air-mixing ratio of heated air and air passing through the bypass passage 103. The radius of gyration of the rotary damper 104 depends on the size of the arc portion 106 so that if the larger outlet is required, the size of the rotary damper 104 effectively increases. Therefore, an outlet having a larger cross-sectional area requires a correspondingly large rotary damper. This requires a relatively large volume of casing 102. Therefore, it is difficult to install the casing 102 in a limited space in an automobile.